Diesel engine



March 6, 1934. 5 v NORDBERG 1,949,577

DIESEL ENGINE Original Filed June 15, 1931 4 Sheets-Sheet 1 abwwvxmmdhmW Gttornegs March 11.9 I 8.1V. E. NORDBERG 77 DIESEL ENGINE OriginalFiled June 15, 1931 4 Sheets-Sheet 3 (Ittomegs March 6, 1934. B. v. E.NORDBERG 9,

DIESEL ENGINE Original Filed June 15, 1951 4 Sheets-Sheet 4 5 5 mww wfif v 11 5 1 was 3nventor Patented Mar. 6, 1934 DIESEL ENGINE Bruno V.E. Nordberg, Milwaukee, Wis., assignor to Nordberg ManufacturingCompany, Milwaukee, Wis., a corporation of Wisconsin Originalapplication June 15, 1931, Serial No. 544,527. Divided and thisapplication April 3,

1933, Serial No. 664,278

17 Claims. I (Cl. 123-33) This invention relates to Diesel engines, andparticularly to the control of Diesel engines of the type describedandelaimed in my prior application Serial No. 342,4,42, filed February25, 1929,

which has since issued as Patent 1,857,256, May

In that prior application was described a method of operating a Dieselengine of the air injection type using a combustible ,gas under pressureto inject the oil in lieu .of: the air customarily used.

The present application is a'division of application Serial No. 544,527,filed June 15, 1931, and is directed to the apparatus. Claims to themethod are presented in the parent application above identified. V

There is a demand for an engine operating on the Diesel cycle and usingeither natural or manufactured gas as itsf-uel, but efforts to providesuch an engine havaheretofore been unsuccess, ful for the reasonothatsuch gases are less combustible than the fuel oils customarily used sothat spontaneous ignition is sluggish particularly if the engine be atall leaky or if the cylinder walls be cold.

According to the invention of the prior application Serial No.342,442,above identified, sufficient fuel oil was furnished to serve as anigniting fuel and this oil was-injected by combustible gas compressed inthesame compressor used for compressing air in the-air; injection Dieselengine. The gas thus serves as the primary fuel and is ignited uponthe-ignition of the more readily combustible oil.

The purpose in substituting gas for oil is economy in those cases wheregas is available more cheaply than oil. For this reason the usualpractice would be to use-the ,minimum quantity of oil which will securear-proper ignition of the gas and to maintain this quantity uniformunder all load 40 conditions. The quantity or oil injected under no-loadconditions-is necessarily less than sufflcient to operate the, ngine atno-load, for the reason that some "gas must be used to inject the oiland this gaslzeipg combustible necessarily furnishes energytojthqrengine. If this condition be met it is possible toflla f thesupply of oil as well as the supply of gas in controlling the engine,but as a rule it is simpler and more economical to maintain the rate ofsupply of oil constant and as low as certain operation will permit.

The invention will now be described from the apparatus standpoint withreference to the accompanying drawings, in which,-

' Fig. 1 is a fragmentary end elevation of a multiple cylinder Dieselengine of the gas injection type.

Fig. 2 is a plan view of the governor and gas control mechanism.

Fig. 3 is a section on the line 3-3 of Fig. 2.

Fig. 4 is an enlarged fragmentary view, partly in'section and partly inelevation, showing the servo-motor mechanism forming part of thegovernor.

Fig. 5 is a perspective view of the servo-motor mechanism and itsconnections.

Fig. 6 is avertical axial section through the gas pressure regulatormechanism.

Fig. 7 is a fragmentary view showing how the governor may be connectedto control the fuel oil pump.

, So far as the general structure of the engine is concerned, it may besaid first that it may be of either the two-cycle or the four-cycletype; may have any type of exhaust mechanism, and may have any type ofscavenging mechanism so far as the present invention is concerned.Further, it may have any desired number of cylinders and any type offuel oil feeding pump which will supply to each injection valve at theproper time a measured quantity of fuel oil for each working cycle. Inaccordance with the practice in air injection Diesels this pump isdriven from the engine in timed relation therewith and furnishes ameasured charge to successive working spaces according to the firingorder.

The simplest scheme is to use the same variable feed fuel pumpcustomarily used with governor control in air injection engines. Thecontrol is disconnected from the governor so that the fuel oil feed isconstant and is set at the desired low rate. This provides an enginewhich may readily be changed over for oil fuel with air injection byconnecting the oil pump control connection to the governor, supplyingair instead of gas to the compressor, and making any necessaryadjustments required by the change of fuel.

Referring first to Fig. 1, which shows a two cycle engine, a portion ofthe engine frame appears at 11, the upper portion of one workingcylinder at 12, the cylinder of the scavenging air pump at 13 and thecylinder structure of the three-stage gas compressor at 14.

The scavenging air pump and themes compressor are, as is usual, drivenfrom the main crank shaft (not shown) and need not difier from thescavenging air pump and the stage compressor used for compressing theblast or injection air in ordinary air-injection Diesel engines, exceptin minor respects.

for blast air.

) portion of riations in bottle In compressing combustible gas theintercoolers customarily used in the blast air compressors, may bedispensed with, though their presence does no harm. In operating onmanufactured gas or other relatively lean gas as contradistinguishedfrom natural gas, the blast compressor should have somewhat greatercapacity than is needed For the above reasons the engine illustratedfollows air injection Diesel engine practices, and in fact is acommercial air injection Diesel engine with minor modifications to adaptit to gas operation. It is readily convertible to operation on the airinjection principle using oil as the sole fuel. If the blast compressorthen has excess capacity, this can be reduced by controlling its intake,as is described in connection with gas operation hereinafter.

The intake for gas is indicated at 15 and the intake regulator valve isgenerally indicated on Fig. 1 at 16, the numeral being applied to thebody of the valve. The blast compressor, indicated generally by thenumeral 14, discharges through pipe 17 to the blast bottle 18. Thepressure in the bottle 18 is communicated to a the intake regulatorvalve 16, whichso controls the action of compressor 14 as to ensuremaintenance of substantially constant pressure in the blast'bottle 18'.

The regulator 16 is illustrated in detail on a larger scale in Fig. 6.In this figure the pipe 19 is shown connected to a surge chamber orreservoir 21, partially filled with oil. From the lower end of thischamber a pipe 22 conducts the oil to the lower end of an adjacentcylinder 23 in which it acts against the lower end of piston 24. Theupper end of piston 24 is in thrust engagement with a cup-like thrustmember 25 which is encircled by a compression spring 26 actingdownwardly on the flange 27 at.the lower end of member '25. The upperend of spring 26 reacts against a spring seat 28 which is adjustable bymeans of the nuts 29 threaded on the tension rods 31.

Thrust member 25 engages thrust roller 32 on lever 33. This is pivotedat 34 to the swinging fulcrum-link 35, and at 36 to the valve stem 37.The body 16 of the valve has upper and lower bonnets 38 and 39 in whichstem 37 is guided, and a double seat 41, 42 for the double beatregulating valve 43. The construction is such that the valve isapproximately balanced, and any equivalent arrangement which will atleast appro mate the result may be substituted.

The stem 37 is made in two parts threaded together as indicated at 44,so as to be adjustable in length, and carries an adjustable spring seat45. Between this seat 45 and bonnet 38 is a compression spring 46 whichserves to hold roller 32 against member 25. The adjustment at 44 permitsready adjustment of the maximum opening of the valve. The adjustment ofspring 26 gives control closing characteristics of valve 43. Grease cupsare shown at 4'7.

As pressure in bottle 18 arises, piston 24 causes gradual closingmovement of valve 43. Since this valve controls the compressor intake,the gas delivered by the compressor is regulated according to demand asindicated by pressure va- 18. Valve 43 is given tapered contours tosecure the desired gradually variable throttling of the intake.

. From the blast bottle 18 is a pipe 48 which leads to the fuelinjection valve 49 (see Figs.

(within necessary limits) of the 1 and 3). This valve is bolted at 51 tothe cylinder head 52 and projects through the cylinder head andterminates in the working space into which it discharges oil and gas.There is one of these valves for each working space in the engine andeach is connected with the bottle 18.

There is also, for each working space in the engine, an oil pump whosecylinder appears at 53, and whose plunger is driven by an eccentric 54on the cam shaft 55 of the engine (see Fig. 1) through eccentric strap56. The cam shaft 55 is 'driven from the engine crank shaft as usual. [na two stroke cycle engine the cam shaft turns at crank shaft speed, andin a four stroke cycle.

engine at half crank shaft speed, as is well under-- stood. The supplyline for fuel oil enters the pump at 5'7 and the pump delivers throughthe pipe 58 to the fuel injection valve 49.

In a Diesel engine in which the fuel oil is merely an igniting fuel forgas, the pumps 53 can be simple constant feed pumps, but in the drawingsis illustrated a type of variable feed pump heretofore used undergovernor control in conventional air injection Diesel engines. In Fig.1, 59 is the inlet valve chamber and 61 the inlet valve stem. Thedischarge valve chamber is at 62. A rocker arm 63 is driven from thepump plunger and swings on eccentric 64. Arm 63 carries a nose 65 whichengages inlet valve stem 61 to hold the inlet valve open during a partof the discharge stroke of the fuel pump. The eccentric 64 is mounted onshaft 66 so that it is possible to vary the quantity of oil dischargedat each pump stroke, by turning the shaft 66 and thus varying theportion of the discharge stroke in which the pump inlet valve is heldopen. In conventional air injection Diesel engines, the governor isconnected to rotate shaft 66. In the present arrangement the governor isnot so connected. The shaft 66 is set to give the desired fuel oil feedrate and remains fixed in such setting while the engine operates. Whenthe engine is shut down it can be turned manually so as to keep thesuction valve open continuously for priming purposes or to cut off allfuel.

The fuel injection valve 49 is best shown in Fig. 3 and conformsgenerally to known design. Within the body is a sleeve 67 through whichthe stem 68 of the needle valve 69 works. The needle valve 69 has a seat71 close to the discharge nozzle 72'. Surrounding sleeve 67 at itsreduced lower end are a plurality of perforated dispersing disks 73which receive the oil and retain it in dispersed condition ready for theaction of the gas blast.

The fuel oil supplied by pump 53 flows through pipe 58 to the annularspace between the body of valve 49 and sleeve 67'where it collects ondisks '73. The bottle 18 is always connected with the space withinsleeve 6'7 by way of pipe48. When needle valve 69 lifts, the gas underpressure from bottle 18, picks up the charge of oil from disks '73 andsprays it through nozzle '72 into the highly compressed air .then in theworking space. The oil ignites, spontaneously igniting the gas and thetwo burn together, producing a true Diesel cycle. In some cases the 'gasprobably also spontaneously ignites, but under certain conditions suchignition of the gas cannot be relied upon.

shaft 55. The cam acts through a rocker arm pivoted at 76, and connectedthrough link 77 with a second rock lever 78 which is connected at 79with valve stem 68.

The rock lever 78 is mounted on a shifting fulcrum which acts to varythe lift of the valve, 69. This fulcrum takes the form of a knife edge81 formed on a sliding block 82. block 82, defined by the guideway 83,is parallel with the straight lower edge of the lever 78 when the valve69 is closed. It follows that the shifting of the block will not movethe valve if the valve is closed. Consequently, shifting of the blockdoes not change the time in the cycle at which the valve opens orcloses, but as the block moves away from the valve stem the height oflift of the valve increases. Increased lift implies wider opening andgreater flow of gas to carry an increase in load or correct for a lossin engine speed. a

' The block 82 is governor-controlled, and, because it requiresconsiderable force to shift the block, a servo-motor is preferablyincluded as a part of the governor.

The governor mechanism is shown generally in Fig. 1 and in detail inFigs. 2 to 4 inclusive.

The casing of an ordinary centrifugal or flyball governor appears at 84and the usual collar which rises as engine speed increases. appears at85. The collar 85 has the usual peripheral groove (not shown) which isengaged by pins 86 on two arms 87 between which the collar 85 turns. Thearms 87 are rigidly connected at their ends by two cross members 88 and89, forming a single rectangular yoke or frame which is pivoted at 91 onthe supporting bracket 92. The bracket 92 is integral with the governorframe or housing. The governor is driven from the cam shaft 55 by anysuitable means such as skew-gears (not shown).

The governor is adjustably loaded by weights 93 which are shiftable inunison relativelyto the fulcrum 91. To effect this the weights aresuspended from rods 94 fixed at their ends in the cross members 88 and.89, and are engaged by threads on the rods 95, which rods are swiveledat their ends in the cross members 88 and 89. The rods may be turned byhand'wheels 96 and are constrained to turn in unison by the gears 97, 98and 99.

.A lug 101 on crossmember 88 is connected by link 102 with floatinglever which controls the valve mechanism of the servo-motor which willnow be described with particular reference to Figs. 4 and 5.

The link 102 ends in a transverse bearing sleeve 104 which lies betweentwo parallel lever arms 105 and is hingedihereto by journal bolts 106.The opposite ends of the arms 105 are supported by a suspender link 107which has a bearing sleeve 108 lying between the arms 105 and hingedthereto by a journal bolt 109. The arms 105 are formed with a pluralityof holes to receive the journal bolts 106 and 109 so that the effectivelever arms may be varied. The upper end of the suspender link 107 ishinged by a journal bolt 111 to the lever 112, which in turn is pivotedat 113 on a bracket 114 carried by bracket 92. The journal bolt 111 isreceived in a longitudinal slot 115 in lever 112, so that it isadjustable toward and from pivot 113.

The outer end of lever 112 is connected by link 116 with the end ofpiston rod 117 of the servomotor. The piston rod 117 is connected withpiston 118 which reciprocates in double-acting oil pressure motorcylinder 119. This cylinder has The path of the combined inlet andexhaust ports 1 21 and 122 at each end, and these ports communicate withthe end portions of; a chamber l23 in which a balanced piston' valve 124r'eciprocates. The piston valve 124 is a combined admission and exhaustvalve, having admission at the middle and exhaust at the ends, and isdesigned with zero lap. Thus in mid-position it just blanks both ports121 and 122, and if shifted slightly in either direction frommid-position connects either of said ports selectively with supply andthe other with exhaust.

The supply connection for oil or other suitable liquid under pressure,appears at 125 in Fig. 5 and leads to the middle portion of chamber 123.

Oil may be supplied under pressure by the lubri on shaft 135 which isrotatable in bearings, onev of which appears at 136, and is urged in-aclockwise direction (as viewed in the drawings) by weighted arm 137.Thus pin 133 is normaliy held at the lower end of slot 132 so that shaft135 rotates as the governor responds to speed variations. For starting(to prevent excess'ive initial supply of gas to the engine) the arm13tmay be lifted and latched in its upward positi0n. .by hinged arm 138which enters a shallow retaining notch 139 in arm 137 (see Fig. 3). Theslot 132 permits this motion. When the engine starts and the governoraffects shaft 135 the arm 138 drops to an inaciive position by gravity.

The shaft 135 carries an arm 141 which is connected by a. link 142 to aradius link 143 and to a drag link 144 which last is connected to theblock 82.

As the engine operates the compressor 13 will furnish scavenging air andthe stage compressor 14 will furnish highly compressed combustible gasfor oil injection and fuel purposes. The compressed combustible gas isstored for use in bottle 18 and the regulator 16 functions as describedto maintain the gas pressure in the bottle substantially constant.

Each oil pump 53 furnishes the corresponding ate to lift thecorresponding needle valves just as the pistons in the working spacesserved by the respective valves approach their dead points.

The height of lift of the needle valve, and consequently the quantity ofcombustible gas which enters the working space during a working stroke,depends on the position of the fulcrum 81, as already explained. Suchposition is controlled by the governor acting through the servo-motor.

The action of the governor may be readily traced. Assume engine speedincreases. 84 rises and levers 87 shift clockwise lowering the rightends of levers 105 and hence lowering valve 124 connected to these linksnear their middles. This causes piston 118 to move upward raising lever112 and hence the left ends of levers Collar 105 until valve 124 oncemore laps ports 121 and 122. v

The upward motion of lever 112 is imparted to arm 134 so that shaft 135turns counterclockwise, shifting block 82 with fulcrum 81 to the leftand reducing the lift of the needle valve 69 to reduce the quanlity ofcombustible gas injected.

If for any reason it is desired that the governor shall control thequantity of fuel oil fed, shafts 135 and 66 may be connected asillustrated in Fig. '7, shaft 66 being then free to turn. To secure thedesired result a link 151 connects an arm 152 fixed on shaft 135 witharm 153 fixed on shaft 66. When shaft 135 turns counterclockwise toreduce the lift of the gas valve, shaft 66 turns clockwise to lowereccentric 64 and cause nose 65 to hold the inlet valve of the fuel oilpump open during a larger portion of the discharge stroke of the fuelpump.

While it is feasible to regulate both oil and gas, regulation of gasalone is preferred, as simpler. Fig. '7 suggests also how the engine maybe converted to air injection operation. In such case link 142 may ormay not be removed according as control of ihe quantity of air is or isnot to be dispensed with. If removed, block 82 must be fixed inposition. r

An important feature of the invention is that the engine is readilyconvertible from gas inject tion operation, for which it is primarilyintended, to air injection operation. This is a desirable feature innatural gas fields, because failure of or increased cost of gas, maymake oil operation necessary.

What is claimed is,-

1. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a valve controlling fioyv throughthe nozzle to the working space; means for actuating said valve;regulating means for varying the amount said valve is opened by said-means; means for supplying charges of fuel oil to said nozzle forsuccessive working strokes; and means for supplying combustible gasunder pressure to said nozzle.

2. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a valve controlling flow throughthe nozzle to the working space; means for actuating said valve,including a rocking lever and a shiftable fulcrum therefor, the partsbeing so arranged that shifting of the fulcrum varies the amount ofopening movement of said valve; regulating means controlling theposition of said fulcrum; means for supplying charges of fuel oil tosaid nozzle for successive working strokes; and means for supplyingcombustible gas under pressure to said nozzle.

3. The combination of claim 2, in which the regulating means includes aspeed responsive governor, and aservo-motor having a follow-up valvemechanism, the governor controling the follow-up valve mechanism, andthe motor being operatively connected with the fulcrum to shift thesame.

4. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a needle valve controlling flowthrough the nozzle to the working space;' means for lifting said valvefrom its seat including a. fulcrum shiftable toward and from the needlevalve and a lever slidably fulcrumed thereon and operatively connectedwith said needle valve, the path of the fulcrum being coincident withthat surface on the lever engaged by the fulcrum when the needle valveis closed; regulating means controlling the shifting of said fulcrum;means for supplying charges of fuel oil to said nozzle for successiveworking strokes; and means for supplying, to saidnozzle, combustible gasunder pressure.

5. The combination of claim 4, in whichvthe regulating means includes a.speed responsive governor, and a servo-motor having a follow-up valvemechanism, the governor controlling the follow-up valve mechanism, andthe motor being operatively connected with the fulcrum to shift thesame.

6. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a needle valve controlling fiowthrough the nozzle to the working space; actuating means for opening andclosing said valve at definite points in the working cycle; meansassociated with said actuating means and modifying the action thereof tovary the degree of opening movement; means for supplying to the nozzle ameasured charge of fuel oil for each working cycle; and means forsupplying combustible gas under pressure to said nozzle.

7. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a variable lift needle'valvecontrolling flow through the nozzle to the working space; actuatingmeans for opening and closing said needle valve at definite points inthe working stroke; means for supplying combustible gas under pressureto said nozzle; adjustable means for furnishing measured charges of fueloil to said nozzle; and controlling means for concurrently varying thelift of said needle valve and the quantity of the measured charge ofoil.

8. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a variable lift needle valvecontrolling fiow through the nozzle to the working space; actuatingmeans for opening and closing said needle valve at definite points inthe working. stroke; means for supplying combustible gas undersubstantially uniform pressure to said nozzle; adjustable means forfurnishing measured charges of fuel oil to said nozzle; and controllingmeans for concurrently varying the lift of said needle valve and thequantity of the measured charge of oil.

9. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a valve controlling flow throughthe nozzle to the working space; actuating means for said valve, capableof opening the same to varying extents in timed relation with theoperation of the engine; adjustable means for furnishing variablecharges of fuel oil to said nozzle; means for supplying combustible gasunder pressure to said nozzle; and a single controlling means forvarying the opening movement of said valve and for varying the quantityY of oil fed in said charges.

10. In a Diesel engine, the combination of a cylinder having a workingspace; a fuel injection nozzle having a valve controlling flow throughthe nozzle to the working space; actuating means for said valve, capableof opening the same to varying extents in timed relation 1 engine;adjustable" responsive governor controlling the extent of Lemar? openingof said valve, and the quantity of fuel oil in said charges.

11. The combination of a Diesel engine having means for injecting fueloil into the working space by means of a combustible gas under pressure;a receiver for storing such gas; a stage compressor for deliveringcombustible gas to said receiver; and means responsive to pressure insaid receiver for regulating the supply of gas to the first stage ofsaid compressor.

12. The combination of a Diesel engine having means for injecting fueloil into the working space by means of a combustible gas under pressure;means for controlling said engine by varying the quantity of gas usedfor such oil injection; a receiver for storing such gas; a stagecompressor for delivering combustible gas to said receiver; and meansresponsive to pressure in said receiver for regulating the supply of gasto the first stage of said compressor.

13. In a convertible Diesel engine, the combination of a cylinder; anadjustable fuel oil injecting valve mechanism therefor, capable ofoperation alternatively by compressed air or compressed combustible gas;a regulable compressor capable of furnishing either air or combustiblegas in suitable quantity to said injecting mechanism; an adjustable oilfeeding device for feeding measured charges of fuel oil to saidinjecting valve mechanisms; a governor; and releasable connections bywhich selectively the governor may regulate the quantity of gas usedduring combustible gas injection, and the quantity of oil used duringair inject-ion.

1a. The combination defined in claim 13 in which the regulablecompressor has a maximum capacity in excess of that required for airinjection, and automatic means are provided to vary the capacity inresponse to the demand.

15. The combination with a Diesel engine having a cylinder of a fuelinjection nozzle; a needle valve controlling flow through the same to 86the cylinder; means for supplying to the nozzle a measured charge offuel oil and combustible gas under pressure, the gas serving to injectthe oil when the needle valve is lifted; means for lifting the needlevalve in timed relation with the operation of the engine; and governingmeans for varying the height of lift of the needle valve.

16. The combination with a Diesel engine having a cylinder of a fuelinjection nozzle; a needle valve controlling flow through the same tothe cylinder; means for supplying to the nozzle a uniform measuredcharge of fuel oil and combustible gas under pressure, the gas servingto inject the oil when the needle valve is lifted; means for lifting theneedle valve in timed relation with the operation of the engine; andgoverning means for varying the height of lift of the needle valve.

17. The combination with a Diesel engine having a cylinder of a fuelinjection nozzle; a needle valve controlling flow through the same tothe cylinder; means for supplying to the nozzle a measured charge offuel oil and combustible gas under pressure, the gas serving to injectthe oil when the needle valve is lifted; means for lifting the needlevalve in timed relation with the operation of the engine; and governingmeans for varying the quantity of gas flowing through the needle valveduring each lift.

BRUNO v. E. NORDBERG.

